1. Field of the Invention
This invention relates to a radiation image recording apparatus for recording a radiation image on a stimulable phosphor sheet. This invention particularly relates to a mobile radiation image recording apparatus which is capable of being moved to a desired location for carrying out the image recording. This invention also relates to a mobile feeding and loading apparatus for stimulable phosphor sheets which is capable of being moved to a desired location for use in the image recording.
2. Description of the Prior Art
When certain kinds of phosphors are exposed to a radiation such as X-rays, .alpha.-rays, .beta.-rays, .gamma.-rays, cathode rays or ultraviolet rays, they store a part of the energy of the radiation. Then, when the phosphor which has been exposed to the radiation is exposed to stimulating rays such as visible light, light is emitted by the phosphor in proportion to the stored energy of the radiation. A phosphor exhibiting such properties is referred to as a stimulable phosphor.
As disclosed in U.S. Pat. No. 4,258,264 and Japanese Unexamined Patent Publication No. 56(1981)-11395, it has been proposed to use a stimulable phosphor in a radiation image recording and reproducing system. Specifically, a sheet provided with a layer of the stimulable phosphor (hereinafter referred to as a stimulable phosphor sheet) is first exposed to a radiation passing through an object such as the human body to have a radiation image of the object stored thereon, and is then scanned by stimulating rays such as a laser beam which cause the stimulable phosphor sheet to emit light in proportion to the stored radiation energy. The light emitted by the stimulable phosphor sheet upon stimulation thereof is photoelectrically detected and converted to electric image signals, and the radiation image of the object is reproduced as a visible image by use of the image signals on a recording medium such as a photographic film, a display device such as a cathode ray tube (CRT), or the like.
The radiation image recording and reproducing system using a stimulable phosphor sheet is advantageous over conventional radiography using a silver halide photographic material in that the image can be recorded over a very wide range (latitude) of radiation exposure. More specifically, since the amount of light emitted upon stimulation after the radiation energy is stored on the stimulable phosphor varies over a wide range in proportion to the amount of said stored energy, it is possible to obtain an image having desirable density regardless of the amount of exposure of the stimulable phosphor sheet to the radiation, by reading out the emitted light with an appropriate read-out gain and converting it into electric signals to reproduce a visible image on a recording medium or a display device.
In the aforesaid radiation image recording and reproducing system, the image recording is first carried out on the stimulable phosphor sheet by use of an image recording apparatus provided with a radiation source. In the case where a patient as the object cannot walk, it is necessary for the image recording apparatus to be conveyed to the sickroom of the patient for recording an image of the patient on the stimulable phosphor sheet. For this purpose, there has heretofore been proposed a small, mobile image recording apparatus composed of a mobile main body having rollers or the like on the bottom surface, and a radiation source mounted on the main body via a supporting arm.
However, the proposed image recording apparatus is constituted so that only the radiation source is mobile. Therefore, with the proposed image recording apparatus, in the case where the image recording is to be carried out by moving the image recording apparatus from sickroom to sickroom, many cassettes each housing a stimulable phosphor sheet capable of being used for the image recording must be carried independently of the image recording apparatus, and it is troublesome to move the image recording apparatus and many cassettes independently of each other from sickroom to sickroom.